Raphael: Hey, Mikey, remember that thing you use to say when we were kids?Michelangelo: You made me promise never to say it again.Raphael: Forget about that. Still got one in the tank?Michelangelo: I've been holding it in for years.Leonardo: Wait, guys, we need a plan!Michelangelo: Cowabunga.

When April O'Neil calls Vernon Fenwick (drives the channel 6 van), he answers his phone and immediately says "O'Neil". When the scene cuts back to O'Neil, we see she called from a payphone. Fenwick would have no way to know it was her calling.